From 5f8de423f190bbb79a62f804151bc24824fa32d8 Mon Sep 17 00:00:00 2001
From: "Matt A. Tobin" <mattatobin@localhost.localdomain>
Date: Fri, 2 Feb 2018 04:16:08 -0500
Subject: Add m-esr52 at 52.6.0

---
 gfx/cairo/quartz-first-stop.patch | 57 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 gfx/cairo/quartz-first-stop.patch

(limited to 'gfx/cairo/quartz-first-stop.patch')

diff --git a/gfx/cairo/quartz-first-stop.patch b/gfx/cairo/quartz-first-stop.patch
new file mode 100644
index 000000000..5ea4b916c
--- /dev/null
+++ b/gfx/cairo/quartz-first-stop.patch
@@ -0,0 +1,57 @@
+diff --git a/gfx/cairo/cairo/src/cairo-quartz-surface.c b/gfx/cairo/cairo/src/cairo-quartz-surface.c
+--- a/gfx/cairo/cairo/src/cairo-quartz-surface.c
++++ b/gfx/cairo/cairo/src/cairo-quartz-surface.c
+@@ -690,31 +690,51 @@ ComputeGradientValue (void *info, const 
+ }
+ 
+ static const float gradient_output_value_ranges[8] = {
+     0.f, 1.f, 0.f, 1.f, 0.f, 1.f, 0.f, 1.f
+ };
+ static const CGFunctionCallbacks gradient_callbacks = {
+     0, ComputeGradientValue, (CGFunctionReleaseInfoCallback) cairo_pattern_destroy
+ };
++/* Quartz will clamp input values to the input range.
++
++   Our stops are all in the range 0.0 to 1.0. However, the color before the
++   beginning of the gradient line is obtained by Quartz computing a negative
++   position on the gradient line, clamping it to the input range we specified
++   for our color function, and then calling our color function (actually it
++   pre-samples the color function into an array, but that doesn't matter just
++   here). Therefore if we set the lower bound to 0.0, a negative position
++   on the gradient line will pass 0.0 to ComputeGradientValue, which will
++   select the last color stop with position 0, although it should select
++   the first color stop (this matters when there are multiple color stops with
++   position 0). 
++   
++   Therefore we pass a small negative number as the lower bound of the input
++   range, so this value gets passed into ComputeGradientValue, which will
++   return the color of the first stop. The number should be small because
++   as far as I can tell, Quartz pre-samples the entire input range of the color
++   function into an array of fixed size, so if the input range is larger
++   than needed, the resolution of the gradient will be unnecessarily low.
++*/
++static const float nonrepeating_gradient_input_value_range[2] = { -0.001f, 1.f };
+ 
+ static CGFunctionRef
+ CreateGradientFunction (const cairo_gradient_pattern_t *gpat)
+ {
+     cairo_pattern_t *pat;
+-    float input_value_range[2] = { 0.f, 1.f };
+ 
+     if (_cairo_pattern_create_copy (&pat, &gpat->base))
+ 	/* quartz doesn't deal very well with malloc failing, so there's
+ 	 * not much point in us trying either */
+ 	return NULL;
+ 
+     return CGFunctionCreate (pat,
+ 			     1,
+-			     input_value_range,
++			     nonrepeating_gradient_input_value_range,
+ 			     4,
+ 			     gradient_output_value_ranges,
+ 			     &gradient_callbacks);
+ }
+ 
+ static void
+ UpdateLinearParametersToIncludePoint(double *min_t, double *max_t, CGPoint *start,
+                                      double dx, double dy,
-- 
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